• 한국기계가공학회지
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• 제7권3호
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• pp.30-35
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• 2008

As demands for being economical, precise drilling process is on the increase. Therefore, the objective of this study is to develop a step cutter that can be controllable through micro dimension and can be changed from separate manufacturing processes of drilling and boring into an integrated one. In order to attain this object the step cutter is designed with a 3D geometric modeling and the design could be modified easily by using parametric modeling methodology. Also, collision is not occurred during manufacturing process because of cutting simulation. The step cutter is assembled by parts made up of 5-axis machining and sintering. Validation tests are accomplished. They show that developed cutter has characteristics such as reduction of machining time as well as the good surface roughness of the machined hole. Indeed, reliability could be obtained from a durability test.

• International Journal of Internet, Broadcasting and Communication
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• 제9권2호
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• pp.20-26
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• 2017

Process control is crucial in many industries, especially in semiconductor manufacturing. In such large-volume multistage manufacturing systems, a product has to go through a very large number of processing steps with reentrant) before being completed. This manufacturing system has many machines of different types for processing a high mix of products. Each process step has specific quality standards and most of them have nonlinear dynamics due to physical and/or chemical reactions. Moreover, many of the processing steps suffer from drift or disturbance. To assure high stability and yield, on-line quality monitoring of the wafers is required. In this paper we develop a real-time fault detection system on semiconductor manufacturing process. Proposed system is superior to other incremental fault detection system and shows similar performance compared to batch way.

• Communications for Statistical Applications and Methods
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• 제22권6호
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• pp.625-637
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• 2015

We develop a Bayesian clustering procedure based on a Dirichlet process prior with cluster specific random effects. Gibbs sampling of a normal mixture of linear mixed regressions with a Dirichlet process was implemented to calculate posterior probabilities when the number of clusters was unknown. Our approach (unlike its counterparts) provides simultaneous partitioning and parameter estimation with the computation of the classification probabilities. A Monte Carlo study of curve estimation results showed that the model was useful for function estimation. We find that the proposed Dirichlet process mixture model with cluster specific random effects detects clusters sensitively by combining vague edges into different clusters. Examples are given to show how these models perform on real data.

• 한국초등과학교육학회지:초등과학교육
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• 제28권3호
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• pp.229-244
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• 2009

This study was initiated to investigate sixth graders' gender characteristics in science problem solving process and thus find out the proper learning and teaching strategies for each gender. A total of 14 students, each of seven male and female students, were selected through three tests, including items of science knowledge, science inquiry, and creativity. Students were required to solve 26 items and to think aloud for researchers help understand how they thought in their problem solving process. Males and females showed some similarity and difference in four steps of problem solving process, understanding, planning, solving, and reviewing. We found gender differences in self-confidence of their answer. This study is expected to help develop teachers' differential teaching strategy for male and female students' science problem solving.

• 품질경영학회지
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• 제31권1호
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• pp.109-122
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• 2003

This paper presents a robust process capability index(PCI) based on the expected loss derived from the empirical distribution function(EDF). We propose the EDF expected loss in order to develop a PCI that does not depends on the underlying process distribution. The EDF expected loss depends only on the sample data, so the PCI based on it is robust and it does nor require complex calculations. The inverted normal loss function(INLF) is employed in order to overcome the drawback of the quadratic loss which may Increase unboundedly outside the specification limits. A comprehensive simulation study was performed under various process distributions, in order to compare the accuracy and the precision of the proposed PCI with those of the PCI based on the expected loss derived from the normal distribution. The proposed PCI turned out to be more accurate than the normal PCI in most cases, especially when the process distribution has high kurtosis or skewness. It is expected that the proposed PCI can be utilized In real processes where the true distribution family may not be known.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2012년도 추계 학술논문 발표대회
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• pp.245-246
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• 2012

Lately the Infill Modular Construction System which meets the domestic standards about the structure and fireproof performance and which is applied to the remodeling techniques is being emphasized. In order to introduce the Infill Modular Construction System to domestic market successfully, the development of insufficient element technologies and systematic analysis of process should be preceded. This research aims to establish of Standard Construction Process, as advanced research for the settlement of the Infill Modular Construction System. As advanced research for the activation of the Infill Modular Construction System, this research aims to develop Infill Unit Module's mobile device. This is expected to improve work efficiency. In addition organizing optimized Standard Construction Process by steady work analysis and improvement is being planned.

• 한국공작기계학회논문집
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• 제12권3호
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• pp.1-7
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• 2003

In-process Electrolytic Dressing is a lapping method using electrolysis. This technology provides dressing to CIB-Diamond Lapping wheels during the lapping process for continuous protrude abrasive from super-abrasive wheels. so loading and glazing are disappeared apparently. Ultra-precision lapping of the machinable commies will be studied in the viewpoint of In-process Electrolytic Dressing. For ultra-precision lapping, need to develop an ultra-precision lapping system suitable metal bonded diamond wheel, and appropriate condition of u10a-precision lapping machining.

• 한국생산제조학회지
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• 제22권1호
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• pp.156-161
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• 2013

Recently, there has been a trend in the manufacturing process to focus on the durability of cable lug joint, especially in welding process due to the poor cable lug joint causes many troubles on products and workers during manufacturing process. Therefore development of high quality cable lug joint is important for successful manufacturing process and safety of worker. The Magnetic Pulse Forming(MPF) is one of efficient way to developed a high quality cable lug joint. In MPF, a high strain rate forming process, utilizes a high velocity oblique collision on the workpiece to be formed in required shape. The objective of this paper is to develop of high quality cable lug joint using electromagnetic force. To successfully accomplish this goal, section and electrical contact temperature of developed cable lug joint has been compared with various cable lug joint. Electrical contact temperature of developed cable lug joint by electromagnetic force is lower than manufactured cable lug joint by pressurer and hydraulic pressurer.

• 산업공학
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• 제23권3호
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• pp.213-220
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• 2010

As the market becomes increasingly globalized and competition among companies increases in severity, various specialized organizations are participating across the process plant lifecycle, including the stages of design, construction, operation and maintenance, and dismantlement, in order to ensure efficiency and elevate competitiveness. In this regard, it is an important technical issue to develop services or information systems for sharing process plant data among participating organizations. ISO 15926 is an international standard for integration of lifecycle data for process plants including oil and gas facilities. ISO 15926 Part 7, a part of the ISO 15926 standard, specifies an implementation method called a facade that uses Web Services and ontology technologies for constructing plant data repositories and related services, with the aim of sharing lifecycle data of process plants. This paper discusses the ISO 15926-based prototype facade implemented for storing equipment data of nuclear power plants and servicing the data to interested organizations.

• 한국공작기계학회논문집
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• 제11권4호
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• pp.89-96
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• 2002

This paper aims to develop an intelligent model for predicting top-bead width for the robotic GMA(Gas Metal Arc) welding process using BP(Back-propagation) neural network and multiple regression analysis. Firstly, based on experimental data, the basic factors affecting top-bead width are identified. Then BP neural network model and multiple regression models of top-bead width are established. The modeling methods and procedure are explained. The developed models are then verified by data obtained from the additional experiment and the predictive behaviors of the two kind of models are compared and analysed. Finally the modeling methods, predictive behaviors md the advantages of each models are discussed.